The collagen content in biopsies from skin and ligamentum rotundum of 7 women with a long history of stress incontinence was compared with that of continent controls. The collagen was extracted with 0.5 M acetic acid, followed by digestion with pepsin and quantitated as hydroxyproline. The skin of stress incontinent women contained 40% less collagen than that of continent women. The findings for ligamentum rotundum were similar. These results suggest a deteriorated connective tissue in stress-incontinent women and cast new light on the etiology of the disease.